Expansion-bolt.



PATBNTED MAR; 31, 1903 H. STEWARD.

EXPANSION BOLT.

APPLICATION FILED SEPT. 1'], 1902. NO MODEL.

V UNITED STATES PATENT OFFICE.

NATHAN HARPER STEWARD, OF PHILADELPHIA, PENNSYLVANIA.

EXPANSION-BOLT.

SPECIFICATION forming part of Letters Patent No. 724,216, dated March 31, 1903. Application filed September 17, 1902. Serial No. 123,733. (No model.)

To all whom it may concern:

Be it known that I, NATHAN HARPER STEW- ARD, a citizen of the United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented new and useful' Improvements in Expansion Bolts, of which the following is a specification.

My invention consists of an expansion-bolt formed of an expansible sleeve, the interior of the same being screw-threaded for the en gagement of a la -screw or bolt and the exteriorbein g provided with means for positively locking the sleeve with the wall of the bore it occupies.

It further consists of the exterior for looking means being of such nature that the sleeve cannot be withdrawn by outward draft nor by rotating the same. a

Figure 1 represents a side elevation of an expansion bolt embodying my invention. Fig. 2 represents a longitudinal section thereof. Fig. 3 represents an end view thereof.

Similar letters of reference indicate corresponding parts in the figures.

Referring to the drawings, A designates an expansion-bolt, the same consisting of the shell B, which is longitudinally divided, forming the sections O, which in the present case are two in number, the interior of said sections being screw-threaded, as at D.

E designates a lag-screw or bolt which is adapted to engage with the threads D of the sections, by which means said sections may be expanded. On the exterior of the sections are serrations F, which extend circumferentially, whereby when the sections are expanded the edges of said serrations penetrate the material of the bore which the sleeve occupies, thus locking the sleeve in position. In the present case one side of each of the serrations extends radially from the sleeves, as at G, and the other side extends obliquely, as at H, from the periphery of the serration to the body of the sleeve, thus forming the sharp edges J, it being evident that When the sections are expanded and tightened in the bore in which the sleeve is locked the radial sides of the teeth interlock with the material of said bore and present shoulders in such manner that the sleeve is retained against outward motion and cannot be withdrawn either by a direct pull or draftor by the rotation of said sleeve, it being noticed that the serrations do not constitute screw-threads, which would permit the rotation of the sleeve'to remove the same. Should it, however, be desired to withdraw the device, the screw or bolt E requires proper rotation, so that it is unscrewed from the sleeve, when the sections are free to close or contract, and thus disengage from their hold, the effect of whichis evident.

As will be seen from Fig. 2, the shell B is formed at its outer end with an unthreaded socket J of greater diameter than the threaded bore, and into this socket is received the unthreaded neck E on the lag-screw or bolt E, a shoulder E being thus formed at the inner end of said neck, which latteris disposed between the head of the bolt and the screwthreads thereof, said shoulder being adapted to abut against the shoulders J at the forward end of said socket. the inward movement of the bolt E.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, 'is v An expansion-bolt formed of a longitudinally-divided sleeve having upon its exterior serrations to form restraining-shoulders and threaded upon its interior and having at its outer end an enlarged socket, and a bolt or screw adapted to expand the sections of the sleeve, and having an enlarged neck to en-' gage in said socket to limit the inward movement of the screw or bolt.

NATHAN HARPER STEWARD. Witnesses:

JOHN A. WIEDERSHEIM, C. D. MoVAY.

This serves to limit I 

